KR20140051120A - Wheel loader - Google Patents

Abstract

A vehicle body 110 having wheels 113 and 114 and a working machine 120 having an arm 121 and a bucket 122 mounted on the entire body 110 and an arm cylinder 123 and a bucket cylinder 124 for driving them, And a work machine operating device 20 for instructing the operation of the working machine 120. The work machine operating device 20 is provided on the right side of the driver's seat 21 Arm-operated lever operation lever 11 and two kick-down switches 16 and 17 provided on the upper and left surfaces of the grip 11a of the arm operation lever 11, respectively. Thus, the operability can be further improved.

Description

Wheel Loader {WHEEL LOADER}

The present invention relates to a wheel loader for piling up and transporting a workpiece.

The working machine of the wheel loader generally includes an arm cylinder for depressing the arm and a bucket cylinder for performing a dump operation or a cloud operation of the bucket and an operation device for instructing the operation of the arm cylinder and the bucket cylinder, (Hereinafter, referred to as " arm operation lever " and " bucket operation lever ", respectively) are provided on the right side of the driver's seat (see Patent Document 1, for example).

International Publication No. WO 2010/147232

Here, the typical operation of the wheel loader is as follows. (A) Moving to the vicinity of a pile of digging material (hereinafter referred to as "mound" as appropriate) of gravel or the like, (B) (C) While pushing the bucket into the dirt, pushing the bucket, the arm is raised while the arm is lifted. At the same time, the bucket is operated in the cloud, and the bucket is pushed up by the bucket. (D) When water is loaded, it moves backward and moves away from the soil and moves to a predetermined place to dump the digger. Among these series of operations, the operation of (A) and (D) does not require a large driving force (pulling force) for pressing the workpiece, so fuel economy is emphasized. A large driving driving force may be required in a timely manner to raise the driving force.

On the other hand, in Patent Document 1, the kick-down switch for rapidly shifting down the gear is temporarily released to the upper portion of the arm operating lever to temporarily release the limitation of the engine top speed to raise the maximum driving driving force And an example in which the change-over switch is provided on the upper portion of the bucket operating lever, respectively. According to this example, when shifting from the operation of (A) to the operation of (B), the kickdown switch is operated to drop to the low speed stage to secure the required driving force, A larger driving force can be obtained by operating the mode changeover switch.

At this time, in the wheel loader of this kind having two operation levers for the arm and the bucket for operating the working machine, the arm operating lever during operation of (B), mainly the bucket operating lever during operation of (C) , Respectively.

(B) are the posture adjustment and the shift down of the bucket. These operations are preliminary to the excavation operation, and are not delicate operations that require subtle adjustment according to progress, but are operations that can be performed even when the arms are leaned lightly on the lever. Therefore, It is varied in color by the hand, or by the operator gripping it from above, and being gripped horizontally.

On the other hand, the operation performed at the time of the operation (C) is to simultaneously instruct the bucket cloud and the advancement of the gas while raising the arm. In the operation (C), it is not good that the maximum driving driving force necessarily increases. For example, there is a case where a large driving force is required after the bucket is pushed into the workpiece. On the other hand, when the vehicle is driven with an excessively large driving force when the driving load due to the workpiece is high, The road surface is pinched by the road surface, which can affect the subsequent operation. (C), it is necessary to raise the maximum driving driving force as necessary while avoiding such a problem, while performing the cloud operation of the bucket according to the ascending operation of the arm.

Therefore, the operation instruction of (C) is required to be performed in a concentrated manner requiring a subtle operation as compared with the operation instruction of (B). Therefore, most operators tend to grasp and operate the bucket operation lever surely.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made in consideration of the actual operating conditions of the operator standing on an easy-to-use stand, and aims to provide a wheel loader capable of further improving operability.

(1) In order to achieve the above-described object, the present invention provides a vehicle comprising: a vehicle body having wheels; a working machine mounted on the entire body of the vehicle; and a working machine operating device for instructing the operation of the working machine, An operation lever for indicating operation of the working machine provided on the side of the driver's seat and two switches provided on the upper surface of the grip of the operation lever and on the side of the driver's seat for operating the pulling force. do.

(2) In the above (1), it is preferable that the working machine has an arm and a bucket, an arm cylinder for driving the arm and the bucket, and a bucket cylinder, A bucket operating lever for guiding the operation of the bucket cylinder and an upper surface of the grip of the arm operating lever and a side surface on the driver's seat side of the driver operating lever, Down switch for forcibly downshifting the speed stage and a plurality of kick down switches provided on the side of the driver's seat side of the grip of the bucket operating lever and having a plurality of upper limit values And a mode changeover switch for changing the running mode.

(3) In the above-mentioned (2), preferably, the mode changeover switch is provided on the upper surface of the grip in addition to the driver's seat side surface or the driver's seat side surface of the grip of the bucket operation lever .

(4) In the above (2) or (3), it is preferable that the mode changeover switch is a push button, and the changeover of a plurality of running modes having different maximum engine speeds .

(5) In any one of (2) to (4), preferably, display means for displaying a running mode selected by the mode changeover switch is provided.

(6) In any one of (2) to (5), preferably, a detent mechanism is provided for maintaining the posture of the arm operating lever at a position instructing the arm lifting operation do.

According to the present invention, the kick-down switch or the mode changeover switch can be flexibly arranged in accordance with the state of the operation of the operator, so that better operability can be ensured.

1 is a side view of a wheel loader according to an embodiment of the present invention.
2 is a block diagram showing a schematic configuration of a drive system provided in a wheel loader according to an embodiment of the present invention.
3 is a running ridge diagram (torque line drawing) showing the relationship between the engine rotational speed and torque when the accelerator pedal is stepped on to the maximum extent in the wheel loader according to the embodiment of the present invention.
4 is a diagram showing the relationship between the vehicle speed and the driving force at each speed stage in the wheel loader according to the embodiment of the present invention.
Fig. 5 is a plan view showing a configuration in a cab of a wheel loader according to an embodiment of the present invention. Fig.
6 is a schematic diagram of a main switch for switching the traveling mode provided in the wheel loader according to the embodiment of the present invention.
Fig. 7 is a schematic view showing the rear view of the appearance of a machine-operating device provided in a wheel loader according to an embodiment of the present invention; Fig.
Fig. 8 is a schematic diagram showing a state in which a work load such as gravel or gravel is loaded on a dump or the like with a wheel loader according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 is a side view of a wheel loader according to an embodiment of the present invention.

The wheel loader 100 shown in Fig. 1 includes a vehicle body 110 and a working machine 120 mounted on the whole of the vehicle body 101. Fig.

The vehicle body 110 is entirely provided with a vehicle body 111 and a rear vehicle body 112. These front and rear vehicle bodies 111 and 112 are provided with front wheels (tires) 113 and rear wheels (tires) 114, respectively, and are capable of bending through the center pins 115 extending in the vertical direction It is connected. Although not shown, all of the vehicle body 111 and the rear body 112 are connected to a steering cylinder, and the vehicle body 111 is entirely bent to the left and right as compared with the rear body 112 due to the extension and retraction of the steering cylinder. On the rear body 112, a cab 116 and a rear engine room 117 are all mounted. The engine room 117 is provided with an engine 131 as a prime mover which will be described later, a hydraulic pump 134 driven by the engine 131, a direction and a flow rate of pressurized oil discharged from the hydraulic pump 134 And a control valve 135 for controlling the operation of the engine.

The working machine 120 has an arm 121 and a bucket 122 and an arm cylinder 123 and a bucket cylinder 124 for driving these arms 121 and the bucket 122. The arm 121 rotates vertically in accordance with the extension and retraction of the arm cylinder 123 and the bucket 122 rotates vertically in accordance with the expansion and contraction drive of the bucket cylinder 124 (a dump operation or a cloud operation )do.

2 is a block diagram showing a schematic configuration of a drive system of the wheel loader 100. As shown in Fig.

2, the drive system 130 of the wheel loader 100 includes an engine 131, a torque converter 132, a transmission 133, a hydraulic pump 134, a control valve 35, a controller 136, an engine control unit 137, a transmission control unit 138, and the like.

The input shaft of the torque converter 132 is connected to the output shaft of the engine 131 and the output shaft of the torque converter 132 is connected to the transmission 133. The torque converter 132 is a fluid clutch composed of a well-known impeller, a turbine and a stator, and the rotation of the engine 131 is transmitted to the transmission 133 via the torque converter 132. The transmission 133 has a hydraulic clutch for shifting its speed stage and the rotation of the output shaft of the torque converter 132 is shifted at the transmission 133. [ The rotation after the shifting is transmitted to the front wheels 113 and the rear wheels 114 via the propeller shaft 141 and the axles 142 so that the wheel loader 100 travels.

The hydraulic pump 134 is of a variable displacement type and is driven by the engine 131 to discharge the pressurized oil. The discharge oil from the hydraulic pump 134 is supplied to the working actuator such as the arm cylinder 123 and the bucket cylinder 124 by controlling the direction and the flow rate via the control valve 135, and these working actuators are driven. The control valve 135 is operated by the arm operating lever 11 and the bucket operating lever 12 (described later) and is operated by the arm cylinder 11 and the bucket operating lever 12 in accordance with operation signals from the arm operating lever 11 and the bucket operating lever 12, 123 and the bucket cylinder 124. The bucket cylinder 124, Further, the pump capacity of the hydraulic pump 134 is changed by a regulator (not shown). The regulator changes the pump capacity according to the pump discharge pressure and performs constant torque control such that the working torque becomes constant, for example. Further, a fixed capacity type pump such as a gear pump may be used for the hydraulic pump 134. [

The controller 136 includes an arithmetic processing unit having a CPU, a ROM, a RAM, and other peripheral circuits. The controller 136 is provided with an accelerator operation amount detector 143 for detecting the operation amount of the accelerator pedal 13 and a vehicle speed detector 144 for detecting the rotational speed of the output shaft of the transmission 133 (or the propeller shaft 141) A rotation speed detector 145 for detecting the rotation speed Ni of the input shaft of the torque converter 132, a rotation speed detector 146 for detecting the rotation speed Nt of the output shaft of the torque converter 132, A forward / reverse switching switch 14 for switching forward (F), reverse (R), and neutral (N) of the speed range switch 100, speed range switch 15 for commanding the upper limit of the speed range between the first speed and fourth speed, Kick down switches 16 and 17 for instructing switching to the low speed side of the vehicle, a power mode for emphasizing workability (hereinafter referred to as " P mode ") or an economy mode A main mode switch 18 (hereinafter referred to as " main switch 18 ") for selecting either one of the traveling modes And a mode changeover switch 19 (hereinafter referred to as " sub-switch 19 ") for selecting a running mode of the same P mode or E mode, respectively.

In the present embodiment, the kick-down switches 16 and 17 and the sub-switch 19 are all push-button switches. At this time, the kick-down switches 16, 17 and the sub-switch 19 are operated so that the operation signal is not output when the finger or palm of the operator is slightly pressed down , The operation signal is not output unless the predetermined clearance is secured and the required stroke is not reduced.

The torque converter 132 has a function of increasing the output torque in comparison with the input torque, that is, a function of making the torque ratio 1 or more. The torque ratio becomes smaller as the torque converter speed ratio e (output rotation speed Nt / input rotation speed Ni), which is the ratio of the rotation speeds of the input shaft and the output shaft of the torque converter 132, increases. For example, when the running load increases during running while the engine rotational speed is constant, the output rotational speed Nt of the torque converter 132, that is, the vehicle speed decreases, and the torque converter speed ratio e becomes small. At this time, since the torque ratio increases, the vehicle can be driven with a larger driving force (traction force). That is, if the vehicle speed is slow, the driving force becomes large (low speed and high torque), and if the vehicle speed is high, the driving force becomes small (high speed low torque).

The transmission 133 is an automatic transmission having a clutch and a solenoid valve corresponding to each speed stage of the first speed-fourth speed. These solenoid valves are driven by control signals output from the controller 136 to the transmission control section 138, and apply pressure to the corresponding clutches to switch the clutches. The controller 136 stores in advance a torque converter speed ratio e1 as a reference for shifting up and a torque converter speed ratio e2 as a reference for a shift down. In the automatic shift mode, the controller 136 calculates the torque converter speed ratio e by a signal from the rotational speed detectors 145 and 146, And outputs a shift-down signal to the transmission controller 138 when the speed ratio becomes smaller than the reference speed ratio e2. Thereby, the speed end of the transmission 133 is automatically changed between the first speed and the fourth speed according to the torque converter speed ratio e.

At this time, the speed stage is automatically shifted with the speed stage selected by the speed stage switch 15 as the upper limit. For example, when the second speed is selected by the speed step switch 15, the speed end is set to one speed or two speeds according to the speed ratio e, and when the first speed is selected, the speed level is fixed to one speed . Although not shown in the drawing, a function of switching from the automatic shift mode to the manual shift mode is provided. In the manual shift mode, the speed stage switch 15 or a switch It is also conceivable to allow a shift.

The kick-down switches 16 and 17 are switches for forcibly down-shifting the speed stage. The controller 136 is connected to the transmission control unit (not shown) whenever one of the kick-down switches 16 and 17 is operated once 138, and forcibly downshifts the speed stage by one stage, regardless of the speed ratio e at that time. In the automatic shift mode, the speed stage can be forcibly shifted down by operating the kick down switch 16 or 17 when, for example, the vehicle speed is low.

In the above, the shift is made when the torque converter speed ratio e exceeds the predetermined value (e1 or e2), but the shift may be made when the vehicle speed reaches the predetermined value. In this case, for example, the shift-up signal or the shift-down signal may be outputted to the transmission control section 138 in accordance with a signal from the vehicle speed detector 144. [

Further, the controller 136 controls the engine rotation speed to the target engine speed according to the operation amount of the accelerator pedal 13. The target engine speed becomes larger when the amount of depression of the accelerator pedal 13 is increased and the controller 136 outputs a control signal corresponding to the target engine speed to the engine control unit 137 to control the engine rotation speed.

3 is a running ridge diagram (torque line diagram) showing the relationship between the engine rotational speed and the torque when the accelerator pedal 13 is stepped on to the maximum degree.

3, the characteristics Ap and Ae are torque line diagrams when the running mode is P mode and E mode, respectively. In the P mode, the engine maximum rotation speed is not limited, whereas in the E mode, the engine maximum rotation speed is limited to the low speed side as compared with the P mode.

The characteristics B0 to B2 are an example of the input torque when the transmission 133 is driven by the engine 131, and the input torque increases as the engine rotation speed increases. This input torque includes the input torque of the hydraulic pump 134. Depending on the torque converter speed ratio e and the absorption torque of the hydraulic pump 134, the input torque is changed as the characteristics B0-B2. Specifically, when the torque converter speed ratio e becomes smaller, the input torque becomes larger (characteristic B0), and when the torque converter speed ratio e becomes larger, the input torque becomes smaller (characteristic B2).

The intersection of the characteristics Ap and Ae and the characteristic B0-B2 is a matching point, and the engine rotation speed is the value of the matching point. Therefore, the engine rotation speed for a predetermined input torque becomes higher in the P mode than in the E mode. When the engine rotational speed is at the matching point, the running driving force is proportional to the square of this engine rotational speed N. [ Therefore, in the P mode, the traveling driving force becomes larger than the E mode, and the maximum vehicle speed at each speed stage is increased by the engine speed.

4 is a diagram showing the relationship between the vehicle speed at each speed stage and the driving driving force. In the figure, the solid line indicates the P mode and the dotted line indicates the characteristic of the E mode.

4, when the vehicle speed is low, the traveling driving force becomes large (low speed and high torque), and when the vehicle speed is high, the traveling driving force becomes small (high speed low torque). Further, as the speed step is smaller, a larger driving driving force can be obtained in the same vehicle speed. That is, the maximum driving force is larger in the P mode than in the E mode, and the maximum vehicle speed is faster. For example, the maximum driving force F2 of the P mode at the second speed stage is greater than the maximum driving force F2 'of the E mode, and the maximum vehicle speed V2hi of the P mode is greater than the maximum vehicle speed V2'hi ).

Fig. 5 is a plan view showing a configuration in the cab 116. Fig.

On the right side of the driver's seat 21, a side console panel 22 and a working machine operating device 20 are provided. The front panel 23 in front of the driver's seat 21 is provided with a steering handle 27, the forward / rearward switching switch 14 and a monitor panel 24. The monitor panel 24 is provided with an E mode and a P And a display unit 25 for displaying which one of the modes is selected. At the front end of the forward / reverse switching switch 14, the above-mentioned speed stage switch 15 is provided. An accelerator pedal 13 and left and right brake pedals 26 are provided below the front panel 23 in front of the driver's seat 21.

In the side console panel 22, the above-mentioned main switch 18 (see FIG. 6) for mode switching is disposed. The main switch 18 is an alternate type switch which can be switched to either the P position for indicating the P mode or the E position for indicating the E mode. The working machine operating device 20 is disposed in front of the side console panel 22 and includes the bucket operating lever 12 for instructing the operation of the bucket cylinder 124 and the bucket operating lever 12 for indicating the operation of the arm cylinder 123 Switch 19 for switching the E mode / P mode in which the upper limit value of the engine maximum rotation speed is different, and two kick down switches 16 and 17 for forcibly downshifting the speed stage ).

7 is a schematic view showing the outer appearance of the machine operation device 20 viewed from the rear side.

7, the arm operating lever 11 is juxtaposed on the right side of the bucket operating lever 12 provided on the right side of the driver's seat 21. As shown in Fig. The above kick down switches 16 and 17 are provided on the upper surface (top portion) and the left surface (the side surface on the driver's seat 21 side) of the grip 11a of the arm operating lever 11. On the other hand, the sub switch 19 for switching the mode is provided on the left side (the side of the driver's seat 21 side) of the grip 12a of the bucket operating lever 12. The sub switch 19 may be provided on the upper surface of the grip 12a in addition to the left side surface or the left side surface of the grip 12a of the bucket operation lever 12 Or may be provided on the upper surface and the left surface of the grip 12a like the kick-down switches 16 and 17). Further, the arm operating lever 11 is provided with a detent mechanism 11b (schematically shown in Fig. 2) for maintaining the posture at a position for instructing the arm elevating operation.

As described above, the kick-down switches 16 and 17 and the sub-switch 19 are push-button type switches, and in the present embodiment, they are all alternator-type push buttons. Therefore, when one of the kick down switches 16 and 17 is operated once, that is, when the vehicle is traveling at a speed other than the first speed (when there is a lower speed step) The shift-down signal is outputted from the controller 136 to the transmission control unit 138 and is shifted down by one step at a low speed. When the kick down switch 16 or 17 is operated at the first step, Go back to speed. However, when the first speed is selected in the speed stage switch 15, the speed stage does not shift in one speed regardless of whether the kick down switches 16 and 17 are operated or not. For the sub-switch 19, the operation is received by the controller 136 only when the E-mode is selected in the main switch 18. That is, when the P mode is selected in the main switch 18, the running mode is fixed to the P mode, and even if the sub switch 19 is operated, the switching signal of the running mode is outputted from the controller 136 to the engine control section 137 And the traveling mode is not switched to the E mode. At this time, the maximum rotation speed of the engine 131 is not limited, the driving driving force can be increased within the range of the capability, and the maximum vehicle speed can be increased. On the other hand, when the E mode is selected in the main switch 18, the mode switch signal is outputted from the controller 136 to the engine control unit 137 when the sub switch 19 is pressed while the vehicle is traveling, When the sub-switch 19 is pressed again, the mode returns to the E mode. In the E mode, the maximum rotational speed of the engine 131 is limited to the low speed side, and the original maximum driving driving force and the maximum vehicle speed are suppressed, thereby improving the fuel economy. After that, every time the sub switch 19 is operated once with the main switch 18 at the E position, the driving mode is P mode, E mode, P mode ... Lt; / RTI >

Next, an example of a typical excavating operation by the wheel loader having the above configuration will be described.

8 is a schematic view showing a state in which a work load such as sand or gravel is loaded on a dump or the like by the wheel loader 100. FIG.

As shown in Fig. 8, when the workpiece is pumped up, typically, (A) the pumice mass P (hereinafter simply referred to as " pumice P & And approaches the dirt (P). At this time, the main switch 18 is set to the E position, and the traveling mode is set to the E mode. (B) The arm operating lever 11 and the bucket operating lever 12 are operated to lower the arm 121 so that the opening of the bucket 122 faces forward, and immediately before entering the soil puddle The kick down switch 16 or 17 is pressed to kick down from the second speed to the first speed. The reason for kicking down to the first speed is that a large driving driving force is required in order to suck the digger into the bucket 122. [

The arm elevating operation is maintained by using the detent mechanism 11b of the arm operating lever 11 (C). As a result, the arm 121 continues to raise the arm even if the operator releases his / her hand from the arm operating lever 11. In addition, during the arm lifting operation, the bucket operation lever 12 is operated to cause the bucket 122 to perform a cloud operation to thereby lift the work piece into the bucket 122. [ When pulling up the workpiece, the driving force (pulling force) is adjusted by accelerating the accelerator pedal (13). At this time, since there is a case where the driving driving force does not rise more than necessary according to the nature of the work and the state of the road surface due to the scooping of the workpiece, and there is a case where a larger driving driving force is required, The E mode and the P mode are timely switched so that the excavated material is pushed up to the bucket 122 while avoiding the slip of the road surface. When the operator pushes the bucket 122 in the bucket 122, the operator manipulates the forward / reverse switch 14 to switch the traveling direction backward and then backward to move away from the soil pile P, (Not shown), and the arm operating lever 11 and the bucket operating lever 12 are operated to feed the digging truck into the load carrier of the dump truck.

Whether either the E mode or the P mode is selected as the traveling mode can be determined by the display signal outputted from the controller 136 based on the operation signal from the main switch 18 and the sub switch 19, 21 on the display section 25 in front of the display section.

According to the present embodiment, the following operational effects can be obtained.

(1) Improvement of operability

When the sub-switch 19 is depressed, the traveling mode is switched to the P mode, so that the hands are released from the working machine operating device 20 during the excavation work, It is not necessary to switch the main switch 18 in the P mode to the P mode, so that good workability can be ensured. In addition, since the running mode can be immediately switched to the P mode regardless of the speed stage by the pushing operation of the sub-switch 19, for example, in the case where the vehicle is running on the back plate in two speeds, It is also useful to increase. When the sub-switch 19 is operated again after the traveling mode is switched to the P mode by the operation of the sub-switch 19, the traveling mode can be returned to the E mode. Therefore, in the state in which the main switch 18 is operated in the E mode, the traveling mode can be arbitrarily switched as desired by the operator, the mode switching operation can be performed quickly and easily, and the traveling driving force can be controlled flexibly have.

Here, generally, the arm operating lever 11 tends to vary in color depending on the situation or the operator's desire, such as grasping the grip 11a firmly or grasping the grip 11a lightly or grasping it from above. Therefore, in the present embodiment, the bucket operating lever 12 is disposed on the left side closer to the operator, the arm operating lever 11 on the far side from the operator, and the kick down switches 16 and 17 for forcibly down- 17 are provided at two places on the upper surface and the left side surface (i.e., the side near the driver's seat 21) of the grip 11a of the arm operating lever 11, and neither of the kick down switches 16, Kick-down operation was made possible. Therefore, when the grip 11a is gripped from above, the kick-down switch 17 disposed on the left side surface of the grip 11a is easily operated by the thumb of the right hand coming to the left of the grip 11a, It is easy to manipulate the kick-down switch 16 provided on the upper surface of the grip 11a with the right-hand thumb. By providing two kick down switches 16 and 17 on the upper surface and the left surface of the grip 11a of the arm operating lever 11 in this manner, the shift down operation can be easily performed Is done.

When the workpiece is lifted up by the bucket 122, it is necessary to perform the operation of bucket cloud, arm elevation and gas advance simultaneously. However, in the arm elevation operation, the detent mechanism 11b of the arm operation lever 11, The operator tends to pull the grip 12a away from the arm operating lever 11 to operate the bucket operating lever 12. [ When the operation of the bucket operating lever 12 is in full operation, a large driving force may be required in a timely manner depending on the circumstances. Even in such a case, the mode switching sub- The sub switch 19 can be operated while holding the bucket operating lever 12 and it is not necessary to release the operating lever 20 or to change the operating lever to switch the traveling mode . In addition, since the sub switch 19 is provided on the left side of the grip 12a, it is easy to switch the traveling mode with the thumb of the right hand placed on the grip 12a.

The kick down switches 16 and 17 and the sub mode switch 19 for switching the traveling mode are divided into the arm operation lever 11 and the bucket operation lever 12 in consideration of the actual operation of the excavation work, By appropriately setting the position and number, the operability can be further improved. By dividing the kick down switches 16 and 17 and the sub mode switch 19 for the traveling mode into the arm operation lever 11 and the bucket operation lever 12, And it is possible to suppress the erroneous operation.

As described above, according to the present embodiment, operability can be further improved.

In addition, even when the operating device 20 is not operated, for example, when driving other than the excavation work, there is a case where it is desired to temporarily increase the driving driving force in the case of running on the back plate. In this case, Since the sub-switch 19 is provided in the bucket operating lever 12 close to the operator, it is easy to switch the traveling mode. This is also useful in securing good operability.

(2) Effect of alternate switch

The kick-down switches 16 and 17 and the mode switching sub-switch 19 are alternate-type switches, so that each of the switches 16, 17 and 19 can arbitrarily select a speed stage or a traveling mode, It is possible to suppress the installation space of each means of the kickdown operation and the switching operation of the traveling mode and to provide a small installation space of the grips 11a and 12a of the arm operation lever 11 and the bucket operation lever 12, 16, 17 and 19 can be appropriately arranged. The fact that the switches 16, 17, and 19 can be arranged in the grips 11a and 12a in this way contributes greatly to the realization of the above-described high operability. Since the switches 16, 17, and 19 are of the alternate type, for example, each of the speed stages is directly selected. Therefore, a plurality of kick down switches may be provided, or two sub- As compared with the case where the switch is installed, the operation mode is simple because one mode can arbitrarily set the running mode or the speed stage.

(3) Ensuring discrimination of driving mode

The selected traveling mode is displayed on the display section 25 of the monitor panel 24 at any time so that the operator can appropriately check the traveling mode on the display section 25 even if the traveling mode is frequently switched by the sub- have. This makes it easy for the operator to set the traveling mode according to his / her intention by performing the operation while confirming the traveling mode appropriately. For example, when the traveling mode is the P mode and the E mode is selected When the driver depresses the accelerator pedal 13 by mistake and the like, the erroneous operation such as rubbing the road surface due to the rise of the driving force against the operator's intention can be suppressed.

In the embodiment described above, the case where the sub-switch 19 for switching the traveling mode is provided only on the left side of the grip 12a of the bucket operating lever 12 has been described as an example. However, And the sub switches 19 may be provided on the upper surface of the grip 12a or on the upper surface and the left surface, respectively (two). Assuming that the grip 12a of the bucket operating lever 12 is gripped from the side, if the mode switching sub switch 19 is located above the grip 12a of the bucket operating lever 12, easy. It is also useful if the sub-switch 19 is located on both the upper and left sides of the grip 12a of the bucket operating lever 12, if the operator grasps the bucket operating lever 12. [

Further, although the case where the sub-switch 19 is an alternate-type switch is exemplified, the sub-switch 19 is assumed to be a temporary and short-time switching operation of the traveling mode. Therefore, even if the same push- It is also conceivable to use a Lys switch. When the momentary switch is employed and the sub switch 19 is depressed when the E mode is selected in the main switch 18, the controller 136 sends a mode switching signal The traveling mode is switched to the P mode only while the sub switch 19 is being depressed and the traveling mode is returned to the E mode when the pressing down of the sub switch 19 is stopped.

Further, when the P mode is selected by the output of the control signal from the controller 136 to the engine control section 137, the maximum rotation speed of the engine 131 is not limited. When the E mode is selected, 131 is limited to the low speed side. However, since the engine maximum rotation speed in the P mode must be shifted to the higher speed side than that in the E mode, it is not necessary to make the engine maximum rotation speed unlimited in the P mode . In addition, although the case where there are two traveling modes E mode and P mode is exemplified, three or more traveling modes in which the upper limit of the engine maximum rotational speed is different may be prepared. In this case, it is preferable that the driving mode is switched in order each time the sub-switch 19 is operated once so that the speed steps are changed by one step each time the kick-down switch 16 or 17 is operated once .

Further, although the torque converter speed ratio e is detected by the rotation speed detectors 145 and 146, the configuration of the speed ratio detection means may be any. The rotation of the engine 131 is transmitted to the front wheels 113 and the rear wheels 114 via the torque converter 132, the transmission 133, the propeller shaft 141 and the axle 142. However, The configuration may be any.

Further, not only the kick-down switches 16 and 17 but also the sub-switch 19, which is a mode changeover switch, can be provided at two positions, that is, the upper surface of the grip of the operation lever and the side surface of the driver's seat 21 side. As in the shift-down operation by the kick-down switches 16 and 17, the shift operation by the sub-switch 19 is also common as an operation related to the pulling force. When the sub-switch 19 is provided at two points of the grip It is possible to contribute to the improvement of the operability at the time of scooping up the soil or the like by the operator or the situation.

Further, although the arm operating lever 11 and the bucket operating lever 12 are provided on the right side of the driver's seat 21 as an example, they may be provided on the left side of the driver's seat 21 as well. It is also preferable that the bucket operating lever 12 is disposed on the driver's seat 21 side of the arm operating lever 11 but the arm operating lever 12 may be provided on the driver's seat side.

At this time, the kick-down switches 16 and 17 and the sub-switch 19 are disposed on the side of the grip 11a of the arm operating lever 11 or the side of the grip 12a of the bucket operating lever 12, The grips 11a and 12a are disposed on the side of the driver's seat 21 side because the grip is assumed to be operated with the thumb when the grip is gripped from above. Therefore, when the arm operating lever 11 and the bucket operating lever 12 are provided on the left side of the driver's seat 21, the kick down switches 16 and 17 are provided on the upper surface of the grip 11a of the arm operating lever 11 And the right side surface. Similarly, when the sub-switch 19 is provided on the side of the grip 12a of the bucket operating lever 12 disposed on the left side of the driver's seat 21, the sub- That is, on the right side surface of the light guide plate 21 side.

11: arm operation lever 11a: grip
1 lb: detent mechanism 12: bucket operating lever
12a: grip 16, 17: kick down switch
19: Sub switch (mode changeover switch) 20: Machine operation device
21: driver's seat 25: display (display means)
100: Wheel loader 110: Body
113: front wheel 114: rear wheel
120: working machine 121: arm
122: bucket 123: arm cylinder
124: Bucket cylinder

Claims (6)

A vehicle body having wheels,
A working machine mounted on the entire body of the vehicle,
And a work machine operating device for instructing the operation of the work machine,
The apparatus control apparatus according to claim 1,
An operating lever for instructing operation of the working machine provided on the side of the driver's seat,
And two switches for operating on an upper surface of the grip of the operation lever and a pulling force provided on the side of the driver's seat side. The method according to claim 1,
The working machine has an arm and a bucket, and an arm cylinder and a bucket cylinder for driving the arms and the bucket,
Wherein said machine operation device comprises:
An arm operating lever for indicating an operation of the arm cylinder as the operating lever,
A bucket operating lever provided on the driver's seat side of the arm operating lever for indicating operation of the bucket cylinder,
Two kick down switches for forcibly downshifting the speed end, the two switches provided on the upper surface of the grip of the arm operating lever and on the side of the driver's seat side,
And a mode changeover switch provided on a side of the driver's seat side of the grip of the bucket operating lever for switching a plurality of running modes having different upper limit values of the engine maximum rotational speed. 3. The method of claim 2,
Wherein the mode changeover switch is provided on the upper surface of the grip in addition to the driver's seat side surface or the driver's seat side surface of the grip of the bucket operation lever. 4. The method according to claim 2 or 3,
Wherein the mode changeover switch is a push button and instructs the switching of a plurality of travel modes different in upper limit of the engine maximum rotation speed as a single unit. 5. The method according to any one of claims 2 to 4,
And display means for displaying a running mode selected by the mode changeover switch. 6. The method according to any one of claims 2 to 5,
And a detent mechanism for maintaining the posture of the arm operating lever at a position indicating the arm lifting operation.

Images